Catch plate for knob latches



May 27, 1930. F. E. BEST ET AL CATCH PLATE FOR KNOB LATCHES Filed Aug.50, 1927 ill lull:

Patented May 27, 1930 UNITED STATES.

PATENT OFFICE.

FRANK ELLISON BEST, OF SEATTLE, AND CARL EVENSEN, OFSEABOLD, WASHINGTON,

ASSIGNORS TO FRANK E. BEST, INC., OF SEATTLE, WASHINGTON, A CORPORATIONOF WASHINGTON CATCH PLATE FOR KNOB LATCI'IES Application filed August30,1927. Serial No. 216,378.

Our invention relates to improvements in auxiliary catches for knobshanks and the object of our invention is to provide simple andefiicient means operable'from one side of a door fastening the shankol'a knob latch so that it can not be turned to retract the bolt, the catchplate means being inaccessible to persons on the other side, usually theoutside, of the door.

Another object is to provide a device of this nature that is adapted foruse in connection with a knob latch of standard construction withoutaltering the parts of the standard knob latch.

More specifieobjects are to provide a catch plate that is adapted to beoperatively disposed between an escutcheon plate of the form commonlycalled a knob rose, and the door, said catch platebeing guided on the"screws that hold the knob rose and having a detent spring cooperatingwith one of said screws for yieldingly holding the catch plate in eitherthe catch or the released position and said catch plate having a slottedportion adapted to engage with and catch the knob shank andfurtherhaving a finger piece extending outwardly from the knob rose plate 1 bywhich it-may be moved.

Other and more specific objects will be ap-;

parent from the following description taken in connection with theaccompanying draw-.

ings.

In the drawings Figure 1 1s a vlew 1n elevation on broken line 1-1 ofFigure 2, showlng' catch plate means constructed in accordance with ourinvention, one half of the knob rose plate being removed.

i r a catch plate constructed in accordance with Figure 2 1s asectionalview on broken line 22 of Figure 1, parts being shown inelevation. r

Figure 3is a detached perspective view of;

the invention. 7

Like reference numerals deslgnate like parts throughout the severalviews.

The device is especially well adapted for use in connection with theknob latches on the doors ofbath rooms and similar places where it isdesired to fasten the door against persons on the outside While the roomis its dished side turned toward the door.

ception of a hub 12. on the knob 10 and said knob rose is ofsubstantially dish shape with All of the previously described partsareof the usual standard construction.

In accordance with ourinvention we provlde an oval shaped catch plate 13of smaller size than the knob rose 6, andhaving a narrower neck 14: onits lower end that terminates in an outwardly bentfinger piece 15. A

block 16 of hardened metal isrigidly secured within a suitable openinginthe central portion of the catch plate 13 and a keyhole shaped slot 17is provided in the hardened block16. An opening 18 is provided in thecatch plate 13 below the block 16 anda flat spring 19 somewhat the shapeof an inverted letter U is secured within the-opening18, said springstraddling the lower screw 7 and serving as a detent to yieldingly holdthe catch plate either in the lowered or released position shownin Fig.1 orin the raised or fastening position shown in Fig. 2. The spring 19is omitted in Fig. 8. It will be notedthat the spring 19 has an enlargedor widened upper end and that the lower ends of said spring are curvedaway from each other. elongated notch 20 in the upper end of the catchplate 13 fits over the upper screw 8 and guides the upper end of saidplate 13.

. A notch 21 at the bottom end oftheknob rose 6 ailords clearance forthe neck 1450i the catch plate and cooperates guiding said fcatch plate.

In installing this look, the knob shank 9 is passed through the keyholeshaped slot 17 the lower screw 7 extendsthrough the open ing 18 andbetween the two leaves of the spring 19 and the'upper screw 8 extendsthrough the notch 20 in the upper end of the catch plate 13. The catchplate is thus slidably disposed within the knob rose 6 between said knobrose and the door.

When the catch plate 13 is moved downwardly into the position shown inFig. l the knob shank will pass through the circular portion ofthekeyhole slot 17 and is free to turn in the usual operation of thelatch. hen the catch plateis raised into the position shown in Fig. 2the narrower portion ofthe keyhole slot 17 will fit over the knob shank9 and prevent the same from being turned thus making it impossible toretract the latch bolt and open the door. The finger piece 15 isconveniently grasped by the fingers when the hand is placed on the doorknob. v

In case of emergency, it is possible, byfirst removing the outside knobof a door, to push the shank 9 inwardly clear of the latch retractingmechanism so that said latch retracting mechanism may be operated by aninstrument, as a screw driver, inserted from the outside and the dooropened.

This catch plate device is simple and cheap in construction, easy toinstall, efiicient and reliable in operation and does not detract fromthe general appearance of the latch bolt.

Obviously changes in the form of construction of the device may be madewithin the scope and spirit of the following claims.

We claim: 1. The combination with a door latch having a substantiallysquare rotatable knob shank provided with knobs and arranged to extendthrough a knob rose plate that is secured by screws to a door, of acatch plate slidable between the knob rose plate and the door and guidedfor movement on said screws, said clatch plate having a keyhole slottherein through which said knob shank extends and a finger piece on saidcatch plate extending outwardly from said knob rose plate.

2. The combination with a door latch includingas a part of its mountinga dished knobrose plate secured to a door by screws, of a catch plateslidable between the knob rose plate and the door, said catch platehaving a slot-through whicha securing screw of the knob rose plateextends, and a detent spring in said slot en aging said screw foryieldingly holding said catch plate in a fastening or a releasedposition.

3. The apparatusas claimed in claim 2 in which the knob rose plate hastwo securing screws arranged one above another and the catch plate hasaguide notch adapted to fit over the screw opposite to the one with whichsaid detent spring cooperates.

4. A catch plate for use in connection with a knob latch comprising anoval body portion,

having a centrally arranged keyhole shaped v slot and provided abovesaid slot with a guide notch and below said slot with a larger open ing,a detent springsecured in said larger opening, a downwardly extendingneck on the bottom end of said body portion and an outwardly projectingfinger piece on the lower end of said neck.

Seattle, Washington, August 25th, 1927. FRANK ELLISON BEST. CARLEVENSEN.

